7-hydroxy-3-(4-methoxyphenyl)-4-benzopyrone

Endpoint summary

Description of key information

Formononetin is not considered to be acutely harmful by the oral or dermal routes.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

6 February - 3 June 2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 425 (Acute Oral Toxicity: Up-and-Down Procedure)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Deviations:

no

GLP compliance:

yes

Test type:

up-and-down procedure

Limit test:

yes

Specific details on test material used for the study:

- Lot No. of test material: 07-170-FIL-2/3
- Appearance: White powder
- Expiration date: May 2010
- Purity: 98.4%
- Storage condition of test material: Room temperature

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Texas Animal Specialties, Humble, TX
- Females nulliparous and non-pregnant: yes
- Age at study initiation: Approx. 9 weeks old
- Weight at study initiation: 200 - 205 g (Day 1 weight); 186 - 190 g (Day 0 fasted weight)
- Fasting period before study: 16 hours before dosing
- Housing: Suspended, wire bottom, stainless steel cage; 1 animal per cage
- Diet: PMI Feeds Inc. Formulab #5008 available ad libitum
- Water: Municipal water supply available ad libitum from automatic water system
- Acclimation period: Not specified

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3°C
- Humidity (%): 30 - 70%
- Air changes (per hr): 10 - 12 air changes/ hour
- Photoperiod (hrs dark / hrs light): 12 hour light/dark cycle

IN-LIFE DATES: 25 February - 13 March 2008

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 40% w/v suspension

MAXIMUM DOSE VOLUME APPLIED: 12.5 mL/kg dose was administered

Doses:

5000 mg/kg

No. of animals per sex per dose:

3 females per dose

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations for mortality and clinical/ behavioural signs of toxicity: at least three times on the day of dosing (Day 0) and at least once daily thereafter for 14 days
- Frequency of weighing: Individual body weights were recorded just prior to dosing and on days 7 and 14 or at the time of discovery after death
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, gross necropsy

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Remarks on result:

not determinable due to absence of adverse toxic effects

Mortality:

There was no mortality during the study.

Clinical signs:

other: All animals appeared normal for the duration of the study.

Gross pathology:

The gross necropsy conducted at termination of the study revealed no observable abnormalities.

Other findings:

- Actual temperature: 20 - 24°C
- Actual relative humidity: 27 - 90% (Humidity was outside of the protocol range but did not affect the study outcome)

Table 1: Body weights, time of death and gross necropsy (Dose level 5000 mg/kg, 12.5 mL/kg)

Animal No.	Dose amount (mL)	Date of dosing	Body weights (g)			Time of death*	Gross necropsy findings
			Day 0	Day 7	Final
201	2.38	26 Feb 08	190	223	243	Day 14	No observable abnormalities
202	2.34	28 Feb 08	187	218	231	Day 14	No observable abnormalities
203	2.32	28 Feb 08	186	220	232	Day 14	No observable abnormalities

* Day of dosing is Day 0; Day 14 is terminal sacrifice

Interpretation of results:

GHS criteria not met

Conclusions:

The acute oral LD50 of the test substance, Formononetin, is estimated to be greater than 5000 mg/kg.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

5 000 mg/kg bw

Quality of whole database:

The acute oral toxicity study is considered reliable and acceptable according to the requirements for REACH.

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

6 February - 3 June 2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1200 (Acute Dermal Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

GLP compliance:

yes

Test type:

fixed dose procedure

Limit test:

yes

Specific details on test material used for the study:

- Lot No. of test material: 07-170-FIL-2/3
- Appearance: White powder
- Expiration date: May 2010
- Purity: 98.4%
- Storage condition of test material: Room temperature

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Texas Animal Specialties, Humble, TX
- Females nulliparous and non-pregnant: yes
- Age at study initiation: Approx. 9 weeks old
- Weight at study initiation: Males 239 - 304 g; Females 165 - 219 g
- Fasting period before study: No
- Housing: Suspended, wire bottom, stainless steel cage; 1 animal per cage
- Diet: PMI Feeds Inc. Formulab #5008 available ad libitum
- Water: Municipal water supply available ad libitum from automatic water system
- Acclimation period: Not specified

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3°C
- Humidity (%): 30 - 70%
- Air changes (per hr): 10 - 12 air changes/ hour
- Photoperiod (hrs dark / hrs light): 12 hour light/dark cycle

IN-LIFE DATES: From: 27 February 2008 To: 13 March 2008

Type of coverage:

semiocclusive

Vehicle:

water

Details on dermal exposure:

TEST SITE
- Area of exposure: The test material was applied to the dorsal surface of the trunk in a thin uniform layer.
- % coverage: Not less than 10% of the total body surface area was clipped
- Type of wrap if used: The area of application was covered with a 5 x 10 cm surgical gauze patch and secured with non-irritating adhesive tape. The trunk of each animal was then wrapped with vet wrap which was secured in place with non-irritating adhesive tape to prevent possible ingestion of the test substance.

REMOVAL OF TEST SUBSTANCE
- Washing: The test sites were gently washed with room temperature tap water and a clean cloth to remove as much residual test material as possible.
- Time after start of exposure: 24 hours

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): The dose amount was 1.21 - 1.54 g in males and 0.823 - 1.01 g in females.
- Concentration (if solution): An individual dose was calculated for each animal based on its Day 0 bodyweight just before exposure.
- Constant volume or concentration used: no
- For solids, paste formed: The test material was moistened with water.

VEHICLE
- Concentration (if solution): Each dose was moistened with a sufficient amount of deionised water at a concentration of 1.0 mL/g of test substance.

Duration of exposure:

24 hours exposure to test material

Doses:

5050 mg/kg

No. of animals per sex per dose:

5 animals/ sex

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations for mortality and clinical/ behavioural signs of toxicity: 2-3 times on the day of exposure (Day 0) and at least once daily thereafter for 14 days
- Frequency of weighing: Individual body weights were recorded just prior to dosing and on days 7 and 14.
- Frequency of dermal irritation observations: approximately 60 minutes after removal of wrappings and on Days 4, 7, 11 and 14.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, gross necropsy

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 050 mg/kg bw

Based on:

test mat.

Remarks on result:

no indication of skin irritation up to the relevant limit dose level

Mortality:

There was no mortality during the study.

Clinical signs:

other: All animals appeared normal for the duration of the study. Irritation included very slight erythema in one animal on Day 1.

Gross pathology:

The gross necropsy conducted at termination of the study revealed no observable abnormalities.

Other findings:

- Actual temperature: 20 - 24°C
- Actual relative humidity: 27 - 90% (Humidity was outside of the protocol range but did not affect the study outcome)

Table 1: Body weights, time of death and gross necropsy (Dose level 5050 mg/kg)

Animal No.	Dose amount (g)	Body weights (g)			Time of death*	Gross necropsy findings
		Day 0	Day 7	Final
251-M	1.21	239	269	284	Day 14	No observable abnormalities
252-M	1.42	282	311	337	Day 14	No observable abnormalities
253-M	1.45	288	318	342	Day 14	No observable abnormalities
254-M	1.41	279	315	346	Day 14	No observable abnormalities
255-M	1.54	304	336	349	Day 14	No observable abnormalities
256-F	0.944	187	198	207	Day 14	No observable abnormalities
257-F	0.914	181	196	212	Day 14	No observable abnormalities
258-F	1.01	200	215	227	Day 14	No observable abnormalities
259-F	1.01	219	237	249	Day 14	No observable abnormalities
260-F	0.823	165	177	189	Day 14	No observable abnormalities

* Day of dosing is Day 0; Day 14 is terminal sacrifice

M – Male

F – Female

Note: Animal 259 dose amount should have been 1.11 g

Interpretation of results:

GHS criteria not met

Conclusions:

The acute dermal LD50 of the test substance, Formononetin, is estimated to be greater than 5050 mg/kg in males and females.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

5 050 mg/kg bw

Quality of whole database:

The acute dermal toxicity study is considered reliable and acceptable according to the requirements for REACH. The endpoint is not required for Annex VII registrations but an acute dermal toxicity study had been performed in 2008 for other regulations and has therefore been submitted as supporting information under REACH.

Justification for classification or non-classification

Oral: The oral LD50 for rats was >5000 mg/kg bw in a study performed in accordance with OECD Guideline 425. Therefore, the substance does not require classification according to the criteria described in Regulation (EC) No. 1272/2008.

Dermal: The dermal LD50 for rats was >5050 mg/kg bw in a study performed in accordance with OECD Guideline 402. Therefore, the substance does not require classification according to the criteria described in Regulation (EC) No. 1272/2008.

Inhalation: Data are not available and are not a requirement for Annex VII REACH registrations.